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Ubiquitous transcription factors display structural plasticity and diverse functions
Author(s) -
NandyMazumdar Monali,
Artsimovitch Irina
Publication year - 2015
Publication title -
bioessays
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.175
H-Index - 184
eISSN - 1521-1878
pISSN - 0265-9247
DOI - 10.1002/bies.201400177
Subject(s) - plasticity , biology , transcription factor , structural plasticity , transcription (linguistics) , evolutionary biology , computational biology , microbiology and biotechnology , genetics , neuroscience , physics , gene , linguistics , philosophy , thermodynamics
Numerous accessory factors modulate RNA polymerase response to regulatory signals and cellular cues and establish communications with co‐transcriptional RNA processing. Transcription regulators are astonishingly diverse, with similar mechanisms arising via convergent evolution. NusG/Spt5 elongation factors comprise the only universally conserved and ancient family of regulators. They bind to the conserved clamp helices domain of RNA polymerase, which also interacts with non‐homologous initiation factors in all domains of life, and reach across the DNA channel to form processivity clamps that enable uninterrupted RNA chain synthesis. In addition to this ubiquitous function, NusG homologs exert diverse, and sometimes opposite, effects on gene expression by competing with each other and other regulators for binding to the clamp helices and by recruiting auxiliary factors that facilitate termination, antitermination, splicing, translation, etc. This surprisingly diverse range of activities and the underlying unprecedented structural changes make studies of these “transformer” proteins both challenging and rewarding.